Printing of With Holding Tax on PO !!!

Hello All

Sorry to bother you again...we have a requirement for printing WH tax in PO.

Scenario is like :

A service PO is created for a domestic vendor and for this company deducts WH tax (range 1-15 % depending on type of service) from the net price.

Now requirement is Client wants that For information purpose WH tax should be printed on PO so that vendor should now why amount paid is less.

For example:

PO has 1 line item for material A qty 1 , price 100 USD. now on PO following values should displayed:

Net Value excluding VAT : 100 USD

Total VAT : 7 USD (7% on above value)

Total Net Value including Tax : 107 USD.

WH tax : 3 USD (3 % on 100 USD)

Net Payable to Supplier after deducting WH tax: 107 USD - 3 USD = 104 USD.

I hope query is clear, now would like to know how we can include WH tax in PO (please note this is just for information purpose and actual calculkation of WH tax happens at the time of Payment to vendor).

Regards

Yogesh